Lightning-arrester



(No Model.)

' G. S'. MAXWELL.

LIGHTNING ARRESTER. No. 423,788. Patented Mar. 18, 1890.

5 ee s I I'm/finite r QM" ewyefi Maxwdl UNITED STATES PATENT OFFICE.

GEORGE SEYMOUR l\'[AX\VEIlIl, OF LOUISVILLE, KENTUCKY.

LlGHTNl NG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 423,788, dated March 18, 1890.

Application filed December 4,1889. Serial No 332,501. (No model.)

T0 aZZ whom it may concern:

Be it known that I, GEORGE SEYMOUR MAX- WELL, a citizen of the United States, residing at Louisville, in the county of Jeiferson and State of Kentucky, have invented certain new and useful Improvements in Lightning-Arresters; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to that class of electrical appliances which are designed to arrest or to divert currents of electricity from any conducting-wire whenever the current becomes so powerful as to endanger any electrical or other apparatus connected with the said wire, such appliances being called lightning-arresters; and the object of the invention is to provide means whereby any electric current which is too strong for safety shall by its own surplus strength actuate the said means to divert the said current to a path of safety.

To this end my invention consists in the construction and combination of parts forming a lightning-arrester, hereinafter described and claimed, reference being had to the ac companying drawing, which is a perspective view of my invention, showing, also, a complete circuit in a theoretical manner.

1 is intended to represent a hand-telephone, which in the present specification is the illstrument to be protected. The circuit shown is completely metallic, and I will trace it from and back to the telephone as follows: By wire 2 to plate 3 thence by wire 4 through one of the coils of an electromagnet 5, and by the same wire 4 to a pillar 6; thence by fine wire 7 to a spring 8, that is connected with abinding-post 9; thence by a wire 10 to the other station 11, and back to the telephone 1 through a series of parts mating those already mentioned-to wit, the wire 10, binding-post 9 spring 8, fine wire 7 pillar 6, and wire 4;, through the other coil of the electro-magnet 5, to and through the aforesaid telephone 1.

12 is arr-armature pivoted at 13 and provided with a cross-bar 14. In its normal position the armature 12 is held far enough from the magnet 5 to be attracted. thereto only when an unsafe charge of electricity enters the magnet, the magnet having been wound to such a degree of resistance as not to be affected by the currents in common service. At the same time the cross-bar 14 is normally held free from the fine wires 7 7.

15 represents a grounding bar, against which either of the springs S 8 would strike if their respective wires 7 7 were broken, and 16 is a wire leading from the bar 15 to the ground.

17 is a wire connectingthe armature 12 with the ground.

The operation is as follows: If a current of dangerous power comes in, when it reaches the electro-magnet 5 its surplus force will attract the armature l2 and bring the cross-bar 14 in contact with the fine wires 7 7 thereby short-circuiting or shunting the electro-magnet 5, which thus loses its magnetism and permits the armature to fall awayfrom the magnet and its cross-bar 14 to fall away from the fine wires 7 7 Now as the full force of the current had been traveling through the wires 7 7 and the crossbar lat, the instant they are separated an arc is formed of sufficient intensity to melt the fine wires 7 7 and allow the springs 8 8 to fly against the bar 15, thus grounding the leading-in circuits and opening or disconnecting the instrument-circuit. The cross-bar 14 and the two fine wires thus act as a circuitbreaker; but I do not limit my claim to the exact form or construction of circuit-breaker here described. The armature 12 and crossbar 14 are provided with a ground-wire 17, so that if the outside circuit were to become crossed with a grounded circuit of high potential, or should receive a charge of lightning while the inside circuit was grounded, the said ground-wire 17 would carry oif the surplus current.

It will be readily seen by persons familiar with the art what modifications of the connections and circuits hereinbefore described would be necessary to adapt the same principle of operation to a grounded circuit; but in my case I wish it to be distinctly understood that I do not claim the wires 7 7, made so fine or with so much resistance that they will be burned off by the direct action of a highpower current in its attempt to pass on them.

I trust to the intensity of resistance of the are described to burn off the said fine wires.

Some of the advantages obtained by the double-ended arm of my arrester-armature are as follows: It is not positively necessary that the armature 12 should be grounded, as at 17,because the contact of its cross-arms 14: with the two fine wires 7 7 short-circuits the current from one wire to the other, and the surplus current will thus be discharged, or else the electro-magnet will act the same as hereinbefore described and form an arc of sufficient intensity to burn the wire and open the circuit, so that if the ground-wire 17 were to be broken it would do no serious harm, though it would leave the action more circuitous. Again, the instrument 1, to be protected, being connected with the two coils of the electro-magnet, is practically in the center of the magnet, and having a fine wire on each end of the outside circuit it obtains every advantage of protection from both sides that it would derive from being located between two magnets without loading the line with the resistance of two magnets.

It in my device one of the fine wires hecomes welded to the armature, that current would be grounded at 17. Then if a too strong current comes in by the other wire the action of the electro-magnetwill be again interposed to cut this other wire and open the circuit. If two magnets with two arinatu res were employed to guard the two wires under similar circumstances and the ground-wire of one of the arinatures became broken, the current would flow through that protector having no ground and through the instrument supposed to be protected thereby and destroy them all.

Having thus fully described my invention, what I believe to be new, and desire to secure by Letters Patent, is the following:

1. In a lightning-arrester, an electro-magnet interposed between the instrument to be protected and the outside circuit, a fine wire connected with each of the two coils of the said magnet and with the outside circuit, an armature for the magnet, provided with a crossbar arranged to engage the said fine wires, a metallic spring communicating between each of the said fine wires and the outside circuit and held under tension by said wires, and a grounding-bar situated to receive the said springs if the said fine wires become broken, substantially as shown and described.

2. The combination, in a1ightning-arrester, of an electro-magnet having one coil of wire connected with one end of anoutside circuitwire and with one side of an instrument to be protected, and having another coil of wire connected with the other end of the said circuit-wire and with the other side of the said instrument, an armature located near the magnet to be attracted thereto only by a current of high potential, and fine wires interposed between the said coils and the outside circuit, the said armature having portions located near the said wires and forming therewith arcs of great resistance, whereby both the said fine wires may be broken.

3. The combinatiomin a lightning-arrester, of an instrument to be protected, a magnet having two coils connected, respectively, with the two sides of the said instrument, a circuit-breaker located between the magnet and the outside circuit, and a ground therefor, substantially as shown and described.

at. In a lightniug-arrester, the combination of a magnet having its two coils connected with the two ends of an outside circuit, fine wires interposed in each of the said two connections, and an armature for the magnet provided with two arms adapted to engage each of the said fine wires, respectively, substantially as shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

GEO. SEYMOUR MAXWELL.

'Witnesses:

M. E. Moons, ELBERT l3. BoHoN. 

